1. Field of the Invention
This invention relates generally to a new method of preparing a crystalline zeolite material and particularly to a new method of making substantially pure zeolite ZSM-39 by utilizing a tetraureacobalt (II) complex and pyrrolidine.
2. Description of the Prior Art
Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversions. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure within which there are a large number of channels. These cavities and channels are precisely uniform in size. Since lthe dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as "molecular sieves" and are utilized in a variety of ways to take advantage of these properties.
Such molecular sieves, both natural and synthetic, include a wide variety of positive ion-containing crystalline aluminosilicates. These aluminosilicates can be described as a rigid three-dimensional framework of SiO.sub.4 and AlO.sub.4 in which the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total aluminum and silicon atoms to oxygen is 1:2. The electrovalence of the tetrahedra containing aluminum is balanced by the inclusion in the crystal of a cation, for example, an alkali metal or an alkaline earth metal cation. This can be expressed wherein the ratio of aluminum to the number of various cations, such as Ca/2, Sr/2, Na, K or Li is equal to unity. One type of cation may be exchanged either entirely or partially by another type of cation utilizing ion exchange techniques in a conventional manner. By means of such cation exchange, it has been possible to vary the properties of a given aluminosilicate by suitable selection of the cation. The spaces between the tetrahedra are occupied by molecules of water prior to dehydration.
Prior art techniques have resulted in the formation of a great variety of synthetic aluminosilicates. These aluminosilicates have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No. 2,882,244), zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat. No. 3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752) zeolite ZSM-5 (U.S. Pat. No. 3,702,886), zeolite ZSM-11 (U.S. Pat. No. 3,709,979) , zeolite ZSM-12 (U.S. Pat. No. 3,832,449) and zeolite ZSM-20 (U.S. Pat. No. 3,972,983), ZSM-23 (U.S. Pat. No. 4,076,842), ZSM-35 (U.S. Pat. No. 4,016,245), ZSM-38 (U.S. Pat. No. 4,046,859), merely to name a few. The preparation of ZSM-5 utilizing a tetraureacobalt (II) complex is described in U.S. Pat. No. 4,100,262.
Zeolite ZSM-39 and its preparation are taught by copending U.S. patent application Ser. No. 084,684 filed Oct. 15, 1979, now abandoned. In this preparation of ZSM-39, the template employed for the synthesis is generally a tetraethylammonium cation or n-propylammine. It has a distinctive X-ray diffraction pattern which identifies it from other known zeolites.